The present invention relates to heterocyclic alkoxyamine compounds, a polymerizable composition comprising a) at least one ethylenically unsaturated monomer and b) a heterocyclic alkoxyamine compound. Further aspects of the present invention are a process for polymerizing ethylenically unsaturated monomers, and the use of heterocyclic alkoxyamine compounds for controlled polymerization. The intermediate N-oxyl derivatives, a composition of the N-oxyl derivatives with ethylenically unsaturated monomers and a free radical initiator, as well as a process for polymerization are also subjects of the present invention. Further subjects of the invention are novel amine precursors and a novel process for manufacturing 5-ring heterocyclic amines.
The compounds of the present invention provide polymeric resin products having low polydispersity. The polymerization process proceeds with enhanced monomer to polymer conversion efficiency. In particular, this invention relates to stable free radical-mediated polymerization processes which provide homopolymers, random copolymers, block copolymers, multiblock copolymers, graft copolymers and the like, at enhanced rates of polymerization and enhanced monomer to polymer conversions.
Polymers or copolymers prepared by free radical polymerization processes inherently have broad molecular weight distributions or polydispersities which are generally higher than about four. One reason for this is that most of the free radical initiators have half lives that are relatively long, ranging from several minutes to many hours, and thus the polymeric chains are not all initiated at the same time and the initiators provide growing chains of various lengths at any time during the polymerization process. Another reason is that the propagating chains in a free radical process can react with each other in processes known as combination and disproportionation, both of which are irreversibly chain-terminating reaction processes. In doing so, chains of varying lengths are terminated at different times during the reaction process, resulting in resins consisting of polymeric chains which vary widely in length from very small to very large and which thus have broad polydispersities. If a free radical polymerization process is to be used for producing narrow molecular weight distributions, then all polymer chains must be initiated at about the same time and termination of the growing polymer-chains by combination or disproportionation processes must be avoided.
Conventional radical polymerization reaction processes pose various significant problems, such as difficulties in predicting or controlling the molecular weight, the polydispersity and the modality of the polymers produced. Furthermore, free radical polymerization processes in bulk of the prior art are difficult to control because the polymerization reaction is strongly exothermic and an efficient heat removal in the highly viscous polymer is mostly impossible. The exothermic nature of the prior art free radical polymerization processes often severely restricts the concentration of reactants or the reactor size upon scale-up.
Due to the above mentioned uncontrollable polymerization reactions, gel formation in conventional free radical polymerization processes are also possible and cause broad molecular weight distributions and/or difficulties during filtering, drying and manipulating the product resin.
U.S. Pat. No. 4,581,429 to Solomon et al., issued Apr. 8, 1986, discloses a free radical polymerization process which controls the growth of polymer chains to produce short chain or oligomeric homopolymers and copolymers, including block and graft copolymers. The process employs an initiator having the formula (in part) Rxe2x80x2Rxe2x80x3Nxe2x80x94Oxe2x80x94X, where X is a free radical species capable of polymerizing unsaturated monomers. The reactions typically have low conversion rates. Specifically mentioned radical Rxe2x80x2Rxe2x80x3Nxe2x80x94Oxe2x80xa2 groups are derived from 1,1,3,3 tetraethylisoindoline, 1,1,3,3 tetrapropylisoindoline, 2,2,6,6 tetramethylpiperidine, 2,2,5,5 tetramethylpyrrolidine or di-t-butylamine. However, the suggested compounds do not fulfill all requirements. Particularly the polymerization of acrylates does not proceed fast enough and/or the monomer to polymer conversion is not as high as desired.
WO 98/13392 describes open chain alkoxyamine compounds which have a symmetrical substitution pattern and are derived from NO gas or from nitroso compounds.
EP-A-735 052 discloses a method for preparing thermoplastic polymers of narrow polydispersities by free radical-initated polymerization, which comprises adding a free radical initiator and a stable free radical agent to the monomer compound.
WO 96/24620 describes a polymerization process in which very specific stable free radical agents are used, such as for example 
WO 98/30601 discloses specific nitroxyls based on imidazolidinons. Nitroxylethers are generically mentioned but not specifically disclosed.
WO 98/44008 discloses specific nitroxyls based on morpholinones, piperazinones and piperazindiones. The nitroxylethers are also generically mentioned but not specifically disclosed.
Despite the above mentioned attempts to improve the control of radical polymerization reactions there is still a need for new polymerization regulators, which are highly reactive, and give an equally good or better control of the molecular weight of the polymer.
Surprisingly it has been found that particularly 5 and 6 membered heterocyclic alkoxyamines or their nitroxyl precursors, which have a high sterical hindrance in xcex1-position to the alkoxyamine group lead to regulators/initiators which allow polymerization very efficient and fast at higher temperatures, but also work at relatively low temperatures such as for example 100xc2x0 C. The higher sterical hindrance may be introduced by at least one higher alkyl substituent than methyl in xcex1-position to the alkoxyamine group. In many cases even higher hindrance by two, three or four higher alkyl groups may be advantageous. The higher sterical hindrance may be also advantageous for 7 and 8 membered heterocyclic alkoxyamines or their nitroxyl precursors.
One subject of the present invention is a polymerizable composition, comprising
a) at least one ethylenically unsaturated monomer or oligomer, and
b) a compound of formula (Ia) or (Ib) 
wherein
R1, R2, R3 and R4 independently of each other are C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C3-C12cycloalkyl radical;
with the proviso that if Q in formula (Ia) is a direct bond, xe2x80x94CH2xe2x80x94 or CO, at least one of R1, R2, R3 or R4 is different from methyl;
R5, R6 and R7 independently are hydrogen, C1-C18alkyl or C6-C10aryl;
X represents a group having at least one carbon atom and is such that the free radical Xxe2x80xa2 derived from X is capable of initiating polymerization of ethylenically unsaturated monomers;
Z1 is O or NR8;
R8 is hydrogen, OH, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-CC18alkenyl, C3-C18alkinyl which are substituted by one or more OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl, C7-C9phenylalkyl, C5-C10heteroaryl, xe2x80x94C(O)xe2x80x94C1-C18alkyl, xe2x80x94Oxe2x80x94C1-C18alkyl or xe2x80x94COOC1-C18alkyl;
Q is a direct bond or a divalent radical CR9R10, CR9R10xe2x80x94CR11R12, CR9R10CR11R12CR13R14, C(O) or CR9R10C(O), wherein R9, R10, R11, R12, R13 and R14 are independently hydrogen, phenyl or C1-C18alkyl;
with the proviso that the compounds (A) and (B) are excluded 
Halogen is F, Cl, Br or I, preferably Cl or Br.
The alkyl radicals in the various substituents may be linear or branched. Examples of alkyl containing 1 to 18 carbon atoms are methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl and octadecyl.
Alkenyl with 3 to 18 carbon atoms is a linear or branched radical as for example propenyl, 2-butenyl, 3-butenyl, isobutenyl, n-2,4-pentadienyl, 3-methyl-2-butenyl, n-2-octenyl, n-2-dodecenyl, iso-dodecenyl, oleyl, n-2-octadecenyl oder n-4-octadecenyl. Preferred is alkenyl with 3 bis 12, particularly preferred with 3 to 6 carbon atoms.
Alkinyl with 3 to 18 is a linear or branched radical as for example propinyl 
2-butinyl, 3-butinyl, n-2-octinyl, oder n-2-octadecinyl. Preferred is alkinyl with 3 to 12, particularly preferred with 3 to 6 carbon atoms.
Examples for hydroxy substituted alkyl are hydroxy propyl, hydroxy butyl or hydroxy hexyl.
Examples for halogen substituted alkyl are dichloropropyl, monobromobutyl or trichlorohexyl.
C2-C18alkyl interrupted by at least one O atom is for example xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94CH3, xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94CH3xe2x80x94 or xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94CH3xe2x80x94. It is preferably derived from polyethlene glycol. A general description is xe2x80x94((CH2)axe2x80x94O)bxe2x80x94H/CH3, wherein a is a number from 1 to 6 and b is a number from 2 to 10.
C2-C18alkyl interrupted by at least one NR5 group may be generally described as xe2x80x94((CH2)axe2x80x94NR5)bxe2x80x94H/CH3, wherein a, b and R5 are as defined above.
C3-C12cycloalkyl is typically, cyclopropyl, cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl or trimethylcyclohexyl.
C6-C10 aryl is for example phenyl or naphthyl, but also comprised are C1-C4alkyl substituted phenyl, C1-C4alkoxy substituted phenyl, hydroxy, halogen or nitro substituted phenyl. Examples for alkyl substituted phenyl are ethylbenzene, toluene, xylene and its isomers, mesitylene or isopropylbenzene. Halogen substituted phenyl is for example dichlorobenzene or bromotoluene.
The C1-C4alkoxy substituents are methoxy, ethoxy, propoxy or butoxy and their corresponding isomers.
C7-C9phenylalkyl is benzyl, phenylethyl or phenylpropyl.
C5-C10heteroaryl is for example pyrrol, pyrazol, imidazol, 2,4, dimethylpyrrol, 1-methylpyrrol, thiophene, furane, furfural, indol, cumarone, oxazol, thiazol, isoxazol, isothiazol, triazol, pyridine, xcex1-picoline, pyridazine, pyrazine or pyrimidine.
Preferred is a composition according, wherein in formula (Ia) and (Ib) R1, R2, R3 and R4 independently of each other are C1-C6alkyl, which is unsubstituted or substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C12alkyl which is interrupted by at least one O atom and/or NR5 group, C5-C6cycloalkyl or C6-C10aryl or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C5-C6cycloalkyl radical.
More preferred is a composition, wherein in formula (Ia) and (Ib) R1, R2, R3 and R4 independently of each other are C1-C4alkyl, which is unsubstituted or substituted by OH, or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C5-C6cycloalkyl radical; and
R5 is hydrogen or C1-C4alkyl.
Preferrably in formula (Ia) and (Ib) R6 and R7 independently are hydrogen, methyl or ethyl.
Preferably in formula (Ia) and (Ib) R8 is hydrogen, C1-C18alkyl, C1-C18alkyl which is substituted by OH; or C7-C9phenylalkyl.
More preferably in formula (Ia) and (Ib) R8 is hydrogen, C1-C4alkyl, C1-C4alkyl which is substituted by OH; phenyl or benzyl.
Preferred is a composition, wherein in formula (Ia) and (Ib) R9, R10, R11, R12, R13 and R14 are independently hydrogen or C1-C4alkyl.
Preferred is a composition, wherein in formula (Ia) and (Ib) Q is a direct bond or a divalent radical CH2, CH2xe2x80x94CH2, CH2xe2x80x94CH2xe2x80x94CH2, C(O) or CH2C(O), CH2xe2x80x94CHxe2x80x94CH3, CH2xe2x80x94CH-phenyl, phenyl-CHxe2x80x94CH2xe2x80x94CH-phenyl, phenyl-CHxe2x80x94CH2xe2x80x94CHxe2x80x94CH3, CH2xe2x80x94CH(CH)3xe2x80x94CH2, C(CH3)2xe2x80x94CH-phenyl or C(CH3)2xe2x80x94CH2xe2x80x94CHxe2x80x94CH3.
Preferably in formula (Ia) and (Ib) X is selected from the group consisting of xe2x80x94CH(aryl)2, xe2x80x94CH2-aryl, 
(C5-C6cycloalkyl)2CCN, C5-C6cycloalkylidene-CCN, (C1-C12alkyl)2CCN, xe2x80x94CH2CHxe2x95x90CH2, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C6-C10)aryl, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94C(O)-phenoxy, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94N-di(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94COxe2x80x94NH(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94COxe2x80x94NH2, xe2x80x94CH2CHxe2x95x90CHxe2x80x94CH3, xe2x80x94CH2xe2x80x94C(CH3)xe2x95x90CH2, xe2x80x94CH2xe2x80x94CHxe2x95x90CH-aryl, 
xe2x80x94Oxe2x80x94C(O)xe2x80x94C1-C12alkyl, xe2x80x94Oxe2x80x94C(O)xe2x80x94(C6-C10)aryl,
(C1-C12)alkyl-CR30xe2x80x94CN, 
wherein
R30 is hydrogen or C1-C12alkyl; and
the aryl groups are phenyl or naphthyl which are unsubstituted or substituted with C1-C12alkyl, halogen, C1-C12alkoxy, C1-C12alkylcarbonyl, glycidyloxy, OH, xe2x80x94COOH or xe2x80x94COOC1-C12alkyl.
Aryl is preferably phenyl, which is unsubstituted or substituted as described above.
More preferred is a composition, wherein in formula (Ia) and (Ib) X is selected from the group consisting of xe2x80x94CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (CH3)2CCN, xe2x80x94CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2 and Oxe2x80x94C(O)-phenyl.
A preferred subgroup of compounds are those of formula (Ia) and (Ib), wherein R1, R2, R3 and R4 independently of each other are C1-C3alkyl, which is unsubstituted or substituted by OH, or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C5-C6cycloalkyl radical;
R5 is hydrogen or C1-C4alkyl.
R6 and R7 independently are hydrogen, methyl or ethyl;
Z1 is O or NR8;
Q is a direct bond or a divalent radical CH2, CH2CH2, CH2xe2x80x94CH2xe2x80x94CH2, C(O), CH2C(O) or CH2xe2x80x94CHxe2x80x94CH3.
R8 is hydrogen, C1-C4alkyl, C1-C4alkyl which is substituted by OH, or benzyl; and
X is selected from the group consisting of CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (CH3)2CCN, CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2.
Another preferred composition is, wherein in formula (Ia) and (Ib) at least two of R1, R2, R3 and R4 are ethyl, propyl or butyl and the remaining are methyl.
Another preferred subgroup is wherein at least three of R1, R2, R3 and R4 are ethyl, propyl or butyl.
The other substituents are as defined above including their preferences.
Particularly preferred is a composition, wherein the compound is of formula (Ic), (Id), (Ie), (If), (Ig) or (Ih) 
wherein R1 to R12 and X have the meaning as defined above including their preferences.
Within the above subgroup the compounds of formula (Id), (Ie), (Ig) or (Ih) are particularly preferred.
A further preferred subgroup within the compounds of formulae (Ic)-(Ih) are those, wherein
R1, R2, R3 and R4 independently of each other are C1-C3alkyl, which is unsubstituted or substituted by OH, or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C5-C6cycloalkyl radical;
R5 is hydrogen or C1-C4alkyl.
R6 and R7 independently are hydrogen, methyl or ethyl;
R8 is hydrogen, C1-C4alkyl, C1-C4alkyl which is substituted by OH, or benzyl;
R9, R10, R11 and R12 are independently hydrogen or C1-C4alkyl; and
X is selected from the group consisting of CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (CH3)2CCN, CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2.
More preferred are those, wherein the compound is of formula (Ie);
R1, R2, R3 and R4 independently of each other are C1-C3alkyl, which is unsubstituted or substituted by OH, or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5,
R5 is hydrogen or C1-C4alkyl.
R8 is hydrogen, C1-C4alkyl, C1-C4alkyl which is substituted by OH, or benzyl;
R9 and R10 are hydrogen; and
X is selected from the group consisting of CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (CH3)2CCN, CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2.
Preferably the ethylenically unsaturated monomer or oligomer is selected from the group consisting of ethylene, propylene, n-butylene, i-butylene, styrene, substituted styrene, conjugated dienes, acrolein, vinyl acetate, vinylpyrrolidone, vinylimidazole, maleic anhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acid salts, (alkyl)acrylic esters, (meth)acrylonitriles, (alkyl)acrylamides, vinyl halides or vinylidene halides.
Preferred ethylenically unsaturated monomers are ethylene, propylene, n-butylene, i-butylene, isoprene, 1,3-butadiene, xcex1-C5-C18alkene, styrene, xcex1-methyl styrene, p-methyl styrene or a compound of formula CH2xe2x95x90C(Ra)xe2x80x94(Cxe2x95x90Z)xe2x80x94Rb, wherein Ra is hydrogen or C1-C4alkyl, Rb is NH2, Oxe2x88x92(Me+), glycidyl, unsubstituted C1-C18alkoxy, C2-C100alkoxy interrupted by at least one N and/or O atom, or hydroxy-substituted C1-C18alkoxy, unsubstituted C1-C18alkylamino, di(C1-C18alkyl)amino, hydroxy-substituted C1-C18alkylamino or hydroxy-substituted di(C1-C18alkyl)amino, xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94N(CH3)2 or xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94N+H(CH3)2Anxe2x88x92;
Anxe2x88x92 is a anion of a monovalent organic or inorganic acid;
Me is a monovalent metal atom or the ammonium ion.
Z is oxygen or sulfur.
Examples of acids from which the anion Anxe2x88x92 is derived are C1-C12carboxylic acids, organic sulfonic acids such as CF3SO3H or CH3SO3H, mineralic acids such as HCl, HBr or HI, oxo acids such as HClO4 or complex acids such as HPF6 or HBF4.
Examples for Ra as C2-C100alkoxy interrupted by at least one O atom are of formula 
wherein Rc is C1-C25alkyl, phenyl or phenyl substituted by C1-C18alkyl, Rd is hydrogen or methyl and v is a number from 1 to 50. These monomers are for example derived from non ionic surfactants by acrylation of the corresponding alkoxylated alcohols or phenols. The repeating units may be derived from ethylene oxide, propylene oxide or mixtures of both.
Further examples of suitable acrylate or methacrylate monomers are given below. 
wherein Anxe2x88x92 and Ra have the meaning as defined above and Re is methyl or benzyl. Anxe2x88x92 is preferably Clxe2x88x92, Brxe2x88x92 or xe2x88x92O3Sxe2x80x94CH3.
Further acrylate monomers are 
Examples for suitable monomers other than acrylates are 
Preferably Ra is hydrogen or methyl, Rb is NH2, gycidyl, unsubstituted or with hydroxy substituted C1-C4alkoxy, unsubstituted C1-C4alkylamino, di(C1-C4alkyl)amino, hydroxy-substituted C1-C4alkylamino or hydroxy-substituted di(C1-C4alkyl)amino; and
Z is oxygen.
Particularly preferred ethylenically unsaturated monomers are styrene, methylacrylate, ethylacrylate, butylacrylate, isobutylacrylate, tert. butylacrylate, hydroxyethylacrylate, hydroxypropylacrylate, dimethylaminoethylacrylate, glycidylacrylates, methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, glycidyl(meth)acrylates, acrylonitrile, acrylamide, methacrylamide or dimethylaminopropyl-methacrylamide.
It is also possible to enhance the rate of polymerization or copolymerization of slowly polymerizing monomers such as for example of the class of methacrylates, in particular methylmethacrylate by the addition of more readily polymerizable comonomers such as acrylates. Typical examples are the polymerization or copolymerization of methylmethacrylate in the presence of methylacrylate or butylacrylate.
Typical slowly polymerizing methacrylates are methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, glycidyl(meth)acrylates, methacrylamide or dimethylaminopropyl-methacrylamide. The polymerization of these methacrylates can be enhanced by the addition of the corresponding acrylates.
Also preferred is a composition, wherein the ethylenically unsaturated monomer is a mixture of a methacrylate and an acrylate.
The amounts of readily polymerizable comonomers range typically from 5 parts to 95 and the slowly polymerizable monomers range from 95 to 5 parts respectively.
The compound of formula (Ia) or (Ib) is preferably present in an amount of from 0.01 mol-% to 30 mol-%, more preferably in an amount of from 0.05 mol-% to 20 mol-%, and most preferably in an amount of from 0.1 mol-% to 10 mol-% based on the monomer or monomer mixture.
Another subject of the invention is a process for preparing an oligomer, a cooligomer, a polymer or a copolymer (block or random) by free radical polymerization of at least one ethylenically unsaturated monomer or oligomer, which comprises (co)polymerizing the monomer or monomers/oligomers in the presence of an initiator compound of formula (Ia) or (Ib) as described above under reaction conditions capable of effecting scission of the Oxe2x80x94X bond to form two free radicals, the radical xe2x80xa2X being capable of initiating polymerization.
Preferably the scission of the Oxe2x80x94X bond is effected by ultrasonic treatment, heating or exposure to electromagnetic radiation, ranging from xcex3 to microwaves.
More preferably the scission of the Oxe2x80x94X bond is effected by heating and takes place at a temperature of between 50xc2x0 C. and 160xc2x0 C., more preferably between 80xc2x0 C. and 150xc2x0 C.
After the polymerization step is completed the reaction mixture may be cooled down to a temperature below 60xc2x0 C., preferably to room temperature. The polymer may be stored at this temperature without further reactions occuring.
The process may be carried out in the presence of an organic solvent or in the presence of water or in mixtures of organic solvents and water. Additional cosolvents or surfactants, such as glycols or ammonium salts of fatty acids, may be present. Other suitable cosolvents are described hereinafter.
Preferred processes use as little solvents as possible. In the reaction mixture it is preferred to use more than 30% by weight of monomer and initiator, particularly preferably more than 50% and most preferrably more than 80%. In many cases it is possible to polymerize without any solvent.
If organic solvents are used, suitable solvents or mixtures of solvents are typically pure alkanes (hexane, heptane, octane, isooctane), aromatic hydrocarbons (benzene, toluene, xylene), halogenated hydrocarbons (chlorobenzene), alkanols (methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether), esters (ethyl acetate, propyl, butyl or hexyl acetate) and ethers (diethyl ether, dibutyl ether, ethylene glycol dimethyl ether), or mixtures thereof.
The aqueous polymerization reactions can be supplemented with a water-miscible or hydrophilic cosolvent to help ensure that the reaction mixture remains a homogeneous single phase throughout the monomer conversion. Any water-soluble or water-miscible cosolvent may be used, as long as the aqueous solvent medium is effective in providing a solvent system which prevents precipitation or phase separation of the reactants or polymer products until after all polymerization reactions have been completed. Exemplary cosolvents useful in the present invention may be selected from the group consisting of aliphatic alcohols, glycols, ethers, glycol ethers, pyrrolidines, N-alkyl pyrrolidinones, N-alkyl pyrrolidones, polyethylene glycols, polypropylene glycols, amides, carboxylic acids and salts thereof, esters, organosulfides, sulfoxides, sulfones, alcohol derivatives, hydroxyether derivatives such as butyl carbitol or cellosolve, amino alcohols, ketones, and the like, as well as derivatives thereof and mixtures thereof. Specific examples include methanol, ethanol, propanol, dioxane, ethylene glycol, propylene glycol, diethylene glycol, glycerol, dipropylene glycol, tetrahydrofuran, and other water-soluble or water-miscible materials, and mixtures thereof. When mixtures of water and water-soluble or water-miscible organic liquids are selected as the aqueous reaction media, the water to cosolvent weight ratio is typically in the range of about 100:0 to about 10:90.
The process is particularly useful for the preparation of block copolymers.
Block copolymers are, for example, block copolymers of polystyrene and polyacrylate (e.g., poly(styrene-co-acrylate) or poly(styrene-co-acrylate-co-styrene). They are usefull as adhesives or as compatibilizers for polymer blends or as polymer toughening agents. Poly(methylmethacrylate-co-acrylate) diblock copolymers or poly(methylacrylate-co-acrylate-co-methacrylate) triblock copolymers) are useful as dispersing agents for coating systeme, as coating additives (e.g. rheological agents, compatibilizers, reactive diluents) or as resin component in coatings(e.g. high solid paints) Block copolymers of styrene, (meth)acrylates and/or acrylonitrile are useful for plastics, elastomers and adhesives.
Furthermore, block copolymers of this invention, wherein the blocks alternate between polar monomers and non-polar monomers, are useful in many applications as amphiphilic surfactants or dispersants for preparing highly uniform polymer blends.
The (co)polymers of the present invention may have a number average molecular weight from 1 000 to 400 000 g/mol, preferably from 2 000 to 250 000 g/mol and, more preferably, from 2 000 to 200 000 g/mol. The number average molecular weight may be determined by size exclusion chromatography (SEC), matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) or, if the initiator carries a group which can be easily distinguished from the monomer(s), by NMR spectroscopy or other conventional methods.
The polymers or copolymers of the present invention have preferably a polydispersity of from 1.1 to 2, more preferably of from 1.2 to 1.8.
Thus, the present invention also encompasses in the synthesis novel block, multi-block, star, gradient, random, hyperbranched and dendritic copolymers, as well as graft copolymers.
The polymers prepared by the present invention are useful for following applications:
adhesives, detergents, dispersants, emulsifiers, surfactants, defoamers, adhesion promoters, corrosion inhibitors, viscosity improvers, lubricants, rheology modifiers, thickeners, crosslinkers, paper treatment, water treatment, electronic materials, paints, coatings, photography, ink materials, imaging materials, superabsorbants, cosmetics, hair products, preservatives, biocide materials or modifiers for asphalt, leather, textiles, ceramics and wood.
Because the present polymerizaton is a xe2x80x9clivingxe2x80x9d polymerization, it can be started and stopped practically at will. Furthermore, the polymer product retains the functional alkoxyamine group allowing a continuation of the polymerization in a living matter. Thus, in one embodiment of this invention, once the first monomer is consumed in the initial polymerizing step a second monomer can then be added to form a second block on the growing polymer chain in a second polymerization step. Therefore it is possible to carry out additional polymerizations with the same or different monomer(s) to prepare multi-block copolymers. Furthermore, since this is a radical polymerization, blocks can be prepared in essentially any order. One is not necessarily restricted to preparing block copolymers where the sequential polymerizing steps must flow from the least stabilized polymer intermediate to the most stabilized polymer intermediate, such as is the case in ionic polymerization. Thus it is possible to prepare a multi-block copolymer in which a polyacrylonitrile or a poly(meth)acrylate block is prepared first, then a styrene or butadiene block is attached thereto, and so on.
Furthermore, there is no linking group required for joining the different blocks of the present block copolymer. One can simply add successive monomers to form successive blocks.
A plurality of specifically designed polymers and copolymers are accessible by the present invention, such as star and graft (co)polymers as described, inter alia, by C. J. Hawker in Angew. Chemie, 1995, 107, pages 1623-1627, dendrimers as described by K. Matyaszewski et al. in Macromolecules 1996, Vol 29, No. 12, pages 4167-4171, graft (co)polymers as described by C. J. Hawker et al. in Macromol. Chem. Phys. 198, 155-166(1997), random copolymers as described by C. J. Hawker in Macromolecules 1996, 29, 2686-2688, or diblock and triblock copolymers as described by N. A. Listigovers in Macromolecules 1996, 29, 8992-8993.
Another subject of the present invention is a polymer or oligomer having attached at least one initiator group xe2x80x94X and at least one oxyamine group of formula (Xa) or (Xb) 
wherein R1 to R7, Q and Z1 are as defined above including their preferences.
The majority of compounds of formula (Ia) and (Ib) is novel and they are consequently also subject of the present invention.
The new compounds are of formula (IIa) or (IIb) 
wherein
R1, R2, R3 and R4 independently of each other are C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C3-C12cycloalkyl radical;
with the proviso that if Q in formula (Ia) is a direct bond, xe2x80x94CH2xe2x80x94 or CO, at least one of R1, R2, R3 or R4 is different from methyl;
R5, R6 and R7 independently are hydrogen, C1-C18alkyl or C6-C10aryl;
X is selected from the group consisting of xe2x80x94CH(aryl)2, xe2x80x94CH2-aryl, 
xe2x80x83xe2x80x94CH2xe2x80x94CH2-aryl, 
xe2x80x83(C5-C6cycloalkyl)2CCN, C5-C6cycloalkylidene-CCN, (C1-C12alkyl)2CCN, xe2x80x94CH2CHxe2x95x90CH2, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C6-C10)aryl, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C12)alkoxy, (C1-C12)alkyl-CR30xe2x80x94C(O)-phenoxy, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94N-di(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94COxe2x80x94NH(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94COxe2x80x94NH2, xe2x80x94CH2CHxe2x95x90CHxe2x80x94CH3, xe2x80x94CH2xe2x80x94C(CH3)xe2x95x90CH2, xe2x80x94CH2xe2x80x94CHxe2x95x90CH-phenyl, 
xe2x80x83xe2x80x94Oxe2x80x94C(O)xe2x80x94C1-C12alkyl, xe2x80x94Oxe2x80x94C(O)xe2x80x94(C6-C10)aryl, (C1-C12)alkyl-CR30xe2x80x94CN, 
wherein
R30 is hydrogen or C1-C12alkyl;
Z1 is O or NR8;
R8 is hydrogen, OH, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by one or more OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl, C7-C9phenylalkyl, C5-C10heteroaryl, xe2x80x94C(O)xe2x80x94C1-C18alkyl, xe2x80x94Oxe2x80x94C1-C18alkyl or COOC1-C18alkyl;
Q is a direct bond or a divalent radical CR9R10, CR9R10xe2x80x94CR11R12, CR9R10CR11R12CR13R14, C(O) or CR9R10C(O), wherein R9, R10, R11, R12, R13 and R14 are independently hydrogen, phenyl or C1-C18alkyl; and
the aryl groups are phenyl or naphthyl which are unsubstituted or substituted with C1-C12alkyl, halogen, C1-C12alkoxy, C1-C12alkylcarbonyl, glycidyloxy, OH, xe2x80x94COOH or xe2x80x94COOC1-C12alkyl;
with the proviso that the compounds (A) and (B) are excluded 
In particular the compounds are of formula (IIc), (IId), (IIe), (IIf), (IIg) or (IIh) 
wherein R1 to R12 have the meaning as defined above and
X is selected from the group consisting of xe2x80x94CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (CH3)2CCN, xe2x80x94CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2 and Oxe2x80x94C(O)-phenyl.
Examples of the different substituents including their preferences have already been given with regard to the composition and apply also for the compounds of formula (IIa) and (IIb).
The compounds of formula (Ia), (Ib), (IIa) or (IIb) in general may be prepared according to standard methods, starting from the corresponding Nxe2x80x94H compound, from which the corresponding Nxe2x80x94Oxe2x80xa2 compounds are prepared, and which are further reacted to the corresponding Nxe2x80x94Oxe2x80x94X compounds. A detailed description is outlined below.
Summary of suitable methods for the preparation of the amine (Nxe2x80x94H) precursors.
1. Subgroup
The compounds of formula 
are for example accessible by reacting an amino alcohol with a ketone and for example chloroform under basic conditions. The resulting hydroxycarboxylate is subsequently reacted to the cyclic lactone 
The reaction is described for 6 membered rings by J. T. Lai.: Synthesis, 122 (1984). The meaning of Q is in this case CR9R10.
2. Subgroup.
The compounds of formula 
are for example accessible by a ring forming reaction with a diol 
The reaction is described for morpholines by J. T. Lai.: Synthesis, 122 (1984). Q has the meaning CR9R10.
3. Subgroup.
The piperazinones of formula 
are prepared by reacting a diamine with chloroform and a ketone in the presence of NaOH (J. T. Lai.: Synthesis, 40 (1981). Q is CR9R10. 
The analogue reaction may be used for the preparation of 7 membered rings (Pyong-nae Son et al.: J. Org. Chem. 46, 323 (1981). Q is CH2xe2x80x94CR9R10.
4. Subgroup.
6-membered rings (piperazindione) of formula 
may for example prepared from aminodinitriles according to E. F. J. Duynstee et al.: Recueil 87, 945 (1968). 
5. Subgroup.
The lactames of formula 
may be prepared by Beckmann rearrangement of the corresponding oximes. Another possibility is the Schmidt-Reaction as described by S. C. Dickermann et. al.: J. Org. Chem. 14, 530, (1949)): 
6. Subgroup.
The preparation of compounds of formula 
is for example described by T. Toda et. al.: Bull. Chem. Soc. Japan, 44, 3445 (1971) or by Te-Chen Tsao et al.: Biotechnol. Prog. 7, 60 (1991).
However the known methods lead only to compounds wherein only two of R1, R2, R3 or R4 are higher alkyl than methyl.
A further subject of the present invention is therefore a process for the preparation of a compound of formula (Vc) 
wherein R1, R2, R3 and R4 are independently C1-C18alkyl, with the proviso that at least 3 are other than methyl and R8 is as defined above; by reacting a 1,1-dialkylglycinamide of formula (XXI) 
with a ketone of formula XXII 
under acid catalysis in an inert solvent to a compound of formula (Vc) 
The reaction is typically carried out in excess of the corresponding ketone or an inert solvent. Suitable solvents or mixtures of solvents are typically pure alkanes (hexane, heptane, octane, isooctane), aromatic hydrocarbons (benzene, toluene, xylene), halogenated hydrocarbons (chlorobenzene), alkanols (methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether), esters (ethyl acetate, propyl, butyl or hexyl acetate) and ethers (diethyl ether, dibutyl ether, ethylene glycol dimethyl ether), or mixtures thereof.
Typical acid catalysts are mineral acids like HCl, H2SO4, BF3, acidic ion-exchanger resins, acidic clays and montmorrilonites or strong organic acids like oxalic acid.
The reaction is carried out under normal pressure at a temperature ranging from room temperature to the boiling temperature of the reaction mixture.
Typically the reaction time is 1 to 100 h, preferably 1 to 20 hours.
The Nxe2x80x94H precursors of the corresponding Nxe2x80x94Oxe2x80x94X compounds of formula (Ia) and (Ib) are partly new.
The new compounds are therefore also subject of the present invention. Subject of the invention is a compound of formula (IVa) or (IVb) 
wherein
R1, R2, R3 and R4 independently of each other are C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl;
R5, R6 and R7 independently are hydrogen, C1-C18alkyl or C6-C10aryl;
Z1 is O or NR8;
R8 is hydrogen, OH, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by one or more OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl, C7-C9phenylalkyl, C5-C10heteroaryl, xe2x80x94C(O)xe2x80x94C1-C18alkyl, xe2x80x94Oxe2x80x94C1-C18alkyl or xe2x80x94COOC1-C18alkyl;
Q is a direct bond or a divalent radical CR9R10, CR9R10xe2x80x94CR11R12, CR9R10CR11R12CR13R14, C(O) or CR9R10C(O), wherein R9, R10, R11, R12, R13 and R14 are independently hydrogen, phenyl or C1-C18alkyl;
with the proviso that if the compounds of formula (IVa) or (IVb) represent a 5, 6 or 7 membered ring at least two of R1, R2, R3 and R4 are different from methyl and the substitution patterns R1, R2, R3, R4 being methyl, methyl, butyl, butyl or methyl, ethyl, methyl, ethyl are excluded.
Preferred is a compound, wherein R1, R2, R3 and R4 independently of each other are C1-C4alkyl, which is unsubstituted or substituted by OH, or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, with the proviso that if the compounds of formula (IVa) or (IVb) represent a 5, 6 or 7 membered ring at least two of R1, R2, R3 and R4 are different from methyl and the substitution patterns methyl methyl, butyl, butyl or methyl, ethyl, methyl, ethyl are excluded;
R5 is hydrogen or C1-C4alkyl.
R6 and R7 independently are hydrogen, methyl or ethyl;
Z1 is O or NR8;
Q is a direct bond or a divalent radical CH2, CH2CH2, CH2xe2x80x94CH2xe2x80x94CH2, C(O), CH2C(O) or CH2xe2x80x94CHxe2x80x94CH3;
R8 is hydrogen, C1-C4alkyl or C1-C4alkyl which is substituted by OH, or benzyl.
More preferred is a compound wherein at least three of R1, R2, R3 and R4 are different from methyl.
Examples of the different substituents including their preferences have already been given and apply also for the compounds of formula (IVa) and (IVb).
As already mentioned the compounds of formula (IVa) and (IVb) are precursors which are oxidized to the corresponding Nxe2x80x94Oxe2x80xa2 compounds.
The oxidation of amines to the corresponding nitroxides is well known and a review is given for example by L. B. Volodarsky, V. A. Reznikov, V. I. Ovcharenko.: Synthetic Chemistry of Stable Nitroxides, CRC Press, Boca Raton 1994.
The Nxe2x80x94Oxe2x80xa2 precursors of the corresponding Nxe2x80x94Oxe2x80x94X compounds of formula (Ia) and (Ib) are also partly new.
These new compounds are therefore also subject of the present invention.
A further subject of the invention is a compound of formula (IIIa) or (IIIb) 
wherein
R1, R2, R3 and R4 independently of each other are C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C3-C12cycloalkyl radical;
R5, R6 and R7 independently are hydrogen, C1-C18alkyl or C6-C10aryl;
Z1 is O or NR8;
R8 is hydrogen, OH, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl, C7-C9phenylalkyl, C5-C10heteroaryl, xe2x80x94C(O)xe2x80x94C1-C18alkyl, xe2x80x94Oxe2x80x94C1-C18alkyl or xe2x80x94COOC1-C18alkyl;
Q is a direct bond or a divalent radical CR9R10, CR9R10xe2x80x94CR11R12, CR9R10CR11R12CR13R14, C(O) or CR9R10C(O), wherein R9, R10, R11, R12, R13 and R14 are independently hydrogen, phenyl or C1-C18alkyl;
with the proviso that in formula (IIIa)
if Q is a direct bond and Z1 is NR8, at least three of R1, R2, R3 or R4 are higher alkyl than methyl;
or if Q is CH2 and Z1 is O, at least one of R1, R2, R3 or R4 is higher alkyl than methyl;
or if Q is CH2 or C(O) and Z1 is NR8 at least two of R1, R2, R3 or R4 are higher alkyl than methyl or one is higher alkyl than methyl and R1 and R2 or R3 and R4 form a C3-C12cycloalkyl radical together with the linking carbon atom.
Preferred is a compound, wherein R1, R2, R3 and R4 independently of each other are C1-C4alkyl, which is unsubstituted or substituted by OH or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5;
R5 is hydrogen or C1-C4alkyl.
R6 and R7 independently are hydrogen, methyl or ethyl;
Z1 is O or NR8;
Q is a direct bond or a divalent radical CH2, CH2CH2, CH2xe2x80x94CH2xe2x80x94CH2, C(O), CH2C(O) or CH2xe2x80x94CHxe2x80x94CH3;
R8 is hydrogen, C1-C4alkyl or C1-C4alkyl which is substituted by OH, or benzyl; with the proviso that in formula (IIIa)
if Q is a direct bond and Z1 is NR8, at least three of R1, R2, R3 or R4 are higher alkyl than methyl;
or if Q is CH2 and Z1 is O, at least one of R1, R2, R3 or R4 is higher alkyl than methyl;
or if Q is CH2 or C(O) and Z1 is NR8 at least two of R1, R2, R3 or R4 are higher alkyl than methyl or one is higher alkyl than methyl and R1 and R2 or R3 and R4 form a C3-C12cycloalkyl radical together with the linking carbon atom.
Examples of the different substituents including their preferences have already been given and apply also for the compounds of formula (IIIa) and (IIIb).
These compounds are intermediates of the title compounds and may also be used together with a radical source to effect polymerization of ethylenically unsaturated monomers or oligomers.
Consequently a further subject of the invention is a polymerizable composition, comprising
a) at least one ethylenically unsaturated monomer or oligomer, and
b) a compound of formula (IIIa) or (IIIb) 
wherein
R1, R2, R3 and R4 independently of each other are C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl or R1 and R2 and/or R3 and R4 together with the linking carbon atom form a C3-C12cycloalkyl radical;
R5, R6 and R7 independently are hydrogen, C1-C18alkyl or C6-C10aryl;
Z1 is O or NR8;
R8 is hydrogen, OH, C1-C18alkyl, C3-C18alkenyl, C3-C18alkinyl, C1-C18alkyl, C3-C18alkinyl, C3-C18alkinyl which are substituted by OH, halogen or a group xe2x80x94Oxe2x80x94C(O)xe2x80x94R5, C2-C18alkyl which is interrupted by at least one O atom and/or NR5 group, C3-C12cycloalkyl or C6-C10aryl, C7-C9phenylalkyl, C5-C10heteroaryl, xe2x80x94C(O)xe2x80x94C1-C18alkyl, xe2x80x94Oxe2x80x94C1-C18alkyl or xe2x80x94COOC1-C18alkyl;
Q is a direct bond or a divalent radical CR9R10, CR9R10xe2x80x94CR11R12, CR9R10CR11R12CR13R14, C(O) or CR9R10C(O), wherein R9, R10, R11, R12, R13 and R14 are independently hydrogen, phenyl or C1-C18alkyl;
with the proviso that in formula (IIIa)
if Q is a direct bond and Z1 is NR8, at least three of R1, R2, R3 or R4 are higher alkyl than methyl;
or if Q is CH2 and Z1 is O, at least one of R1, R2, R3 or R4 is higher alkyl than methyl;
or if Q is CH2 or C(O) and Z1 is NR8 at least two of R1, R2, R3 or R4 are higher alkyl than methyl or one is higher alkyl than methyl and R1 and R2 or R3 and R4 together with the linking carbon atom form a C3-C12cycloalkyl radical;
c) a free radical source capable of initiating polymerization of ethylenically unsaturated monomers.
Preferred is a composition, wherein the compound is of formula (IIIc), (IIId), (IIIe), (IIIf), (IIIg) or (IIIh) 
wherein R1 to R12 have the meaning as defined defined above.
Examples for the different substituents including their preferences have already been given. They apply also for the compounds in the above composition.
The production of C-centered radicals is described, inter alia, in Houben Weyl, Methoden der Organischen Chemie, Vol. E 19a, pages 60-147. These methods can be applied in general analogy.
The source of radicals may be a bis-azo compound, a peroxide or a hydroperoxide.
Preferably, the source of radicals is 2,2xe2x80x2-azobisisobutyronitrile, 2,2xe2x80x2-azobis(2-methylbutyronitrile), 2,2xe2x80x2-azobis(2,4-dimethylvaleronitrile), 2,2xe2x80x2-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1xe2x80x2-azobis(1-cyclohexanecarbonitrile), 2,2xe2x80x2-azobis(isobutyramide) dihydrate, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, dimethyl-2,2xe2x80x2-azobisisobutyrate, 2-(carbamoylazo)isobutyronitrile, 2,2xe2x80x2-azobis(2,4,4-trimethylpentane), 2,2xe2x80x2-azobis(2-methylpropane), 2,2xe2x80x2-azobis(N,Nxe2x80x2-dimethyleneisobutyramidine), free base or hydrochloride, 2,2xe2x80x2-azobis(2-amidinopropane), free base or hydrochloride, 2,2xe2x80x2-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} or 2,2xe2x80x2-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide.
Preferred peroxides and hydroperoxides are acetyl cyclohexane sulphonyl peroxide, diisopropyl peroxy dicarbonate, t-amyl perneodecanoate, t-butyl perneodecanoate, t-butyl perpivalate, t-amylperpivalate, bis(2,4-dichlorobenzoyl)peroxide, diisononanoyl peroxide, didecanoyl peroxide, dioctanoyl peroxide, dilauroyl peroxide, bis (2-methylbenzoyl) peroxide, disuccinic acid peroxide, diacetyl peroxide, dibenzoyl peroxide, t-butyl per 2-ethylhexanoate, bis-(4-chlorobenzoyl)-peroxide, t-butyl perisobutyrate, t-butyl permaleinate, 1,1-bis(t-butylperoxy)3,5,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, t-butyl peroxy isopropyl carbonate, t-butyl perisononaoate, 2,5-dimethylhexane 2,5-dibenzoate, t-butyl peracetate, t-amyl perbenzoate, t-butyl perbenzoate, 2,2-bis (t-butylperoxy) butane, 2,2 bis (t-butylperoxy) propane, dicumyl peroxide, 2,5-dimethylhexane-2,5-di-t-butylperoxide, 3-t-butylperoxy 3-phenylphthalide, di-t-amyl peroxide, xcex1,xcex1xe2x80x2-bis(t-butylperoxy isopropyl) benzene, 3,5-bis (t-butylperoxy)3,5-dimethyl 1,2-dioxolane, di-t-butyl peroxide, 2,5-dimethylhexyne-2,5-di-t-butylperoxide, 3,3,6,6,9,9-hexamethyl 1,2,4,5-tetraoxa cyclononane, p-menthane hydroperoxide, pinane hydroperoxide, diisopropylbenzene mono-xcex1-hydroperoxide, cumene hydroperoxide or t-butyl hydroperoxide.
These compounds are commercially available.
If more than one radical source is used, a mixture of substitution patterns is obtainable.
The molar ratio of the radical source to the compound of formulae IIIa or IIIb may be from 1:10 to 10:1, preferably from 1:5 to 5:1 and more preferably from 1:2 to 2:1.
The NOX compounds are prepared for example by reacting the Nitroxides with free radicals. The radicals may be generated by scission of peroxy- or azo compounds as for example described by T. J. Connolly, M. V. Baldovi, N. Mohtat, J. C. Scaiano.: Tet. Lett. 37, 4919 (1996) or by I. Li, B. A. Howell et al.: Polym. Prepr. 36, 469 (1996). Suitable examples are given above.
Another possibility is a halogen atom transfer from a alkylhalogenide in the presence of Cu(I) as described by K. Matyjaszewski.: Macromol. Symp. 111, 47-61 (1996).) or a one electron oxidation as described by P. Stipa, L. Greci, P. Carloni, E. Damiani.: Polym. Deg. Stab. 55, 323 (1997))
Further possibilities are the O-alkylation of the corresponding hydroxylamine, as for example described by Said Oulad Hammouch, J. M. Catala.: Macromol. Rapid Commun. 17, 149-154 (1996), Meisenheinmer rearrangement of the corresponding N-Allyl-N-oxids as described by B. Walchuk et al.: Polymer Preprints 39, 296 (1998) or the reaction of a oxoammonium salt with a carbonyl compound, as described by Tan Ren, You-Cheng Liu, Qing-Xiang Guo.: Bull. Chem. Soc. Jpn. 69, 2935 (1996).
Still further subjects of the invention are the use of a compound of formula (Ia) or (Ib) and the use of a compound of formula (IIIa) or (IIIb) together with a free radical source as defined above for the polymerization of ethylenically unsaturated monomers or oligomers.
The following examples illustrate the invention.